Sealable carton

ABSTRACT

A carton and blank for forming a carton for accommodating a pizza or the like, comprising a top, a base panel, a pair of oppositely disposed side panels interconnecting said top and said base to provide a flat tubular structure and an end closure arrangement to close opposite ends of the carton including end flaps adjoining said top and said base panel and a corner closure structure at each corner of the carton including a plurality of overlapping gusset panels wherein each said gusset panel adjoins a respective said side panel, said end flap and one of said top panel or said base panel.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This is a divisional application of U.S. patent application No.09/355,702 filed Sep. 27, 1999, now abandoned.

BACKGROUND OF THE INVENTION

[0002] 1. Technical Field of the Invention

[0003] The invention relates to sealable cartons, and more particularlyto sealable cartons having diagonal corner blanks for forming suchcartons.

[0004] 2. Background of the Invention

[0005] A tray-like shallow carton having angled (or diagonal) comers isa convenient means for packaging many items, particularly generally flatfood items such as pizza. The angled corners provide a geometricstructure that strengthens the carton by increasing its load bearingcapacity. The contents of such a carton are protected from damage thatmight occur from loads typically placed upon the carton. An example of atypical load is the weight produced when multiple cartons are stackedone upon another for shipping and/or storage. Often, although the angledcorner structure is beneficial the resulting geometric configurationresults in a substantially open or openable corner structure throughwhich contaminants may enter. What is needed is a diagonally corneredcarton whose angled corners inhibit the entrance of contaminants intothe carton.

[0006] Blanks for forming cartons are made from paperboard or othersuitable material. It is highly desirable to minimise the amount ofexcess carton forming material when such blanks are made. Preferably theblank should be manufactured with a minimum of excess carton formingmaterial.

BRIEF SUMMARY OF THE INVENTION

[0007] According to one aspect of the invention, there is a carton foraccommodating a pizza or the like, comprising a top, a base panel, apair of oppositely disposed side panels interconnecting said top andsaid base to provide a flat tubular structure and an end closurearrangement to close opposite ends of the carton including at eachcorner of the carton a corner panel hinged to adjacent side wall and topand base and having means for attachment to further end flaps hinged tosaid top and bottom panels.

[0008] According to one optional feature, said corner panel may bedisplaced inwardly of said end flaps.

[0009] According to another optional feature, the corner panel maycomprise a central panel adapted to provide a bevelled corner to saidcarton and a gusset panel hinged to said central panel and said top anda second gusset panel hinged to said central panel and said base whereinsaid gusset panels extend outwardly from said central panel and adaptedto provide a sealed corner of said carton.

[0010] According to another aspect of the invention, there is a blankfor forming a flat tubular carton comprising a top panel, a base panel,a pair of oppositely disposed side and end walls hingeably connected tosaid top panel and/or said base panel and an end closure arrangementincluding a corner panel hingeably connected to a side wall and a gussetpanel connected to said corner panel and one of said top panel and/orsaid base panel.

[0011] According to one optional feature of this aspect of the inventionsaid corner panel may be hingeably connected to said top panel and saidbase panel.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0012] Embodiments of the invention will now be described, by way ofexample only, with reference to the accompanying drawings in which:

[0013]FIG. 1 is a plan view of a blank for forming a sealable cartonaccording to a preferred embodiment of the invention;

[0014]FIG. 2 is an isometric illustration of a carton fully closed andsealed;

[0015]FIG. 3 is a plan view of a blank for forming a sealable containeraccording to a second preferred embodiment of the invention;

[0016]FIG. 4 is an isometric illustration of a carton erected from ablank of FIG. 3 fully closed and sealed;

[0017]FIG. 5 is a plan view of a blank for forming a sealable cartonaccording to a third preferred embodiment of the invention;

[0018]FIG. 6 is an isometric illustration of a carton erected from ablank of FIG. 5 fully closed and sealed;

[0019]FIG. 7 is a plan view of a blank for forming a sealable cartonaccording to a fourth embodiment of the invention;

[0020]FIG. 8 is an isometric illustration of a carton erected from ablank of FIG. 7 fully closed and sealed;

[0021]FIG. 9 is a plan view of a blank for forming a sealable cartonaccording to a fifth embodiment of the invention; and

[0022]FIG. 10 is an isometric illustration of a carton erected from ablank of FIG. 9 fully closed and sealed.

DETAILED DESCRIPTION OF THE INVENTION

[0023] Referring first to FIG. 1, there is illustrated a blank 10 forforming a sealable carton according to a preferred embodiment of theinvention. The carton blank is made from paperboard or other similarfoldable sheet material. The blank comprises a first side panel 12, atop panel 14, a second side panel 16, a base panel 18, an outer sidepanel 20 hingeably connected one to the next along fold lines22,24,26,28 respectively.

[0024] An end flap 30 is hingeably connected to a side edge of top panel14 along fold line 32. A second end flap 34 is hingeably connected tothe opposing side edge of top panel 14 along fold line 36. Likewise, anend flap 38 is hingeably connected to a side edge of base panel 18 alongfold line 40. A second end flap 42 is hingeably connected to theopposing side edge of base panel 18 along fold line 44.

[0025] Top panel 14 and base panel 18 include a pair of fold lines46,48; 50,52 extending longitudinally between side panel 12, side panel16 and side panel 16, side panel 20 respectively.

[0026] A corner panel 54 is hingeably connected to a side edge of sidepanel 12 along fold line 56. Corner panel 54, is hingeably connected togusset panel 58 along lateral fold line 60, which in this embodiment isan extension of fold line 22. Gusset panel 58 is substantially arcuatein shape and is hingeably connected to top panel 14 along fold line 62.Fold line 62 extends outwardly from the intersection of fold lines 56and 60, to the intersection of the free edges of top panel 14 and gussetpanel 58.

[0027] Similarly, a second corner panel 64 is hingeably connected to theopposing side edge of side panel 12 along fold line 66. A second gussetpanel 68 hingeably connects corner panel 64 and top panel 14. Cornerpanel 64 and gusset panel 68 are in symmetrically opposite positions tocorner panel 54 and gusset panel 58 and are of similar construction andnot therefore more specifically described.

[0028] A corner panel 70 is hingeably connected to a side edge of outerside panel 20 along fold line 72. Corner panel 70, is hingeablyconnected to gusset panel 74 along lateral fold line 76, which in thisembodiment is an extension of fold line 28. Gusset panel 74 issubstantially arcuate in shape, being hingeably connected to base panel18 along fold line 78. Fold line 78 extends outwardly from theintersection of fold lines 28 and 72, to the intersection of the freeedges of base panel 18 and gusset panel 74.

[0029] Similarly, a second corner panel 88 is hingeably connected to theopposing side edge of side panel 20 along fold line 86. A second gussetpanel 84 hingeably connects corner panel 88 and base panel 18. Cornerpanel 88 and gusset panel 86 are in symmetrically opposite positions tocorner panel 70 and gusset panel 74 and are of similar construction andnot therefore more specifically described.

[0030] As shown in FIG. 1, a pair of corner panels 92,108 is struck fromopposing side edges of the side panel 16. In particular, corner panel 92is hingeably connected to a side edge of side panel 16 along fold line94. Fold line 44 extends longitudinally between fold line 46 and foldline 50. A glue flap 96 is hingeably connected along the opposing sideedge of corner panel 92 along fold line 98. Gusset panels 100 and 102are hingeably connected to opposing upper and lower edges of cornerpanel 92 by fold lines 101,103 respectively. Fold lines 101 and 103 arelateral extensions of fold lines 24 and 26 respectively.

[0031] Gusset panel 100 is substantially arcuate in shape and ishingeably connected to top panel 14 along fold line 104. Fold line 104extends outwardly from the intersection of fold lines 94 and 24, to theintersection of the free edges of top panel 14 and gusset panel 100.Likewise, gusset panel 102 is substantially arcuate in structure andhingeably connected to base panel 18 along fold line 106. Fold line 106extends outwardly from the intersection of fold lines 94 and 26, to theintersection of the free edges of base panel 18 and gusset panel 102.

[0032] Likewise, the opposing side edge of side panel 16 is hingeablyconnected to a corner panel 108 which also comprises a pair of gussetpanels 110 and 112 and a glue flap 114. The aforementioned panels are insymmetrically opposite positions to corner panel 92, gusset panels100,102 and glue flap 96 and are of similar construction and nottherefore more specifically described.

[0033] Turning to the construction of the carrier, illustrated in FIG.2, side panel 12 is folded about fold line 22 and into substantiallyperpendicular relationship with top panel 14, thereby folding cornerpanels 54 and 64 into substantially perpendicular relationship withgusset panels 58 and 68 respectively. Top panel 14 and base panel 18 arefolded into a spaced face to face relationship. More specifically, sidepanel 16 is folded into substantially perpendicular relationship withtop panel 14 and base panel 18 about fold lines 24 and 26 respectivelysuch that top panel 14 and base panel 18 are aligned but separated byside panels 12 and 16.

[0034] Central panels 92 and 108 are in a perpendicular relationshipwith respective pairs of gusset panels 100,102 and 110,112. Outer sidepanel 20 is folded about fold line 28 into substantially perpendicularrelationship with base panel 18 and into a face to face relationshipwith side panel 12. It will be appreciated by those skilled in the artthat panels 12 and 20 can be interchanged so that, for example panel 12could form the outer side panel, according to particular manufacturingrequirements.

[0035] Side panels 12 and 20 and, preferably, corner panels 54,70 and64,88 are secured together by glue or other means known in the artthereby forming a flat tubular structure.

[0036] The carrier is in a part erected condition and is able to receiveflat food items, for example a pizza, from either end of the carton. Thepizza is inserted from one side and to avoid the pizza being caught oneither the base or top panel, part of the top panel 14 and bottom panel18 are temporarily folded out of alignment with the rest of aforesaidpanels about fold lines 46 and 50 or, depending on the point of entry ofthe pizza, fold lines 48 and 52. The temporary folds 46,48; 50,52 alsoprovide flexibility to the top and base panels when constructing thecorner structures.

[0037] Once the flat food item has been placed within the carton, thecorner structures are then formed. Corner panel 92, is folded in aninward direction about fold line 94 such that gusset panels 100 and 102are also folded out of alignment. More particularly, gusset panel 100 isfolded about fold line 104 and into a face to face relationship with toppanel 14 such that a substantially perpendicular relationship is formedwith corner panel 92 about fold line 101. Likewise gusset panel 102 isfolded about fold line 106 and into a substantially face to facerelationship with base panel 18 such that a substantially perpendicularrelationship is formed with corner panel 92 about fold line 103.

[0038] Likewise, corner panels 70,54 are folded inwardly such thatgusset panels 74 and 58 are folded in substantially the same way asgusset panels 100 and 102 described above. Thereafter glue flaps 80,96are folded into an angular relationship with corner panels 92 and 70respectively and end flaps 30 and 38 are folded about fold lines 32 and40 and into a perpendicular relationship with top panel 14 and basepanel 18 respectively. End flaps 30 and 38 are connected together byglue or other means known in the art and connected to glue flaps 80 and96 by glue or other means known in the art. An end structure E isthereby formed, as illustrated in FIG. 2.

[0039] The opposing end structure incorporating corner panels 88,64 and108 and end flaps 34,42 is constructed in a similar way to corner panels54,70 and 92 and end flaps 30,38 and are therefore not described in anygreater detail. Thus, the carton is in its completed form illustrated inFIG. 2.

[0040] Turning to the second embodiment illustrated in FIGS. 3 and 4,the blank is substantially similar to the embodiment illustrated inFIGS. 1 and 2 with side panels 150,154,158, top and base panels 152,156and end flaps and therefore only the differences are described in anygreater detail. In this embodiment, the corner structures comprise acorner panel 160 hingeably connected to side panel 154 about fold line162. A gusset panel 164 is hingeably connected to the upper edge ofcorner panel 160 along fold line 166. Gusset panel 164 is connected totop panel 152 by means of a connecting portion 168 which is hingeablyconnected to gusset panel 164 along fold line 170 and is hingeablyconnected to top panel 152 along fold line 172. Gusset panel 164 ispositioned adjacent to top panel 152 but separated therefrom by cut line174 which extends from the inner edge of fold line 172 to theintersection of fold lines 162 and 166.

[0041] Likewise, a gusset panel 176 is hingeably connected to the loweredge of corner panel 160 along fold line 178. Gusset panel 176 isconnected to base panel 156 by means of a connecting portion 180 whichis hingeably connected to gusset panel 176 along fold line 182 and ishingeably connected to base panel 156 along fold line 184. Gusset panel176 is positioned adjacent to base panel 156 but separated therefrom bycut line 186 which extends from the inner edge of fold line 184 to theintersection of fold lines 162 and 178.

[0042] The other corner structures are formed in substantially the sameway as corner panel 160 and gusset panels 164,176 and are therefore notdescribed in any greater detail.

[0043] The construction of the corner structure is carried out after thecarton is partly erected into a flat tubular structure as describedearlier. The corner structure is formed by folding corner panel 160inwardly towards the adjacent end flaps by folding corner portions 168and 180 about fold lines 172,170 and 184,182 respectively such thatcorner portion 168 is in a face to face relationship with top panel 152and corner portion 180 is in a face to face relationship with base panel156. Gusset panels 164 and 176 are folded out of alignment and intosubstantially perpendicular relationship with corner panel 160 such thatcorner portion 168 forms a face to face relationship with gusset panel164 and corner portion 180 forms a face to face relationship with gussetpanel 176. Preferably, gusset panel 164 is secured to top panel 152 byglue or other means known in the art. Likewise, gusset panel 176 ispreferably secured to base panel 156 by glue or other means known in theart. The other corner structures are constructed in the same way, asunderstood by those skilled in the art, and the end flaps securetogether to form the carton in its completed sealed form as illustratedin FIG. 4.

[0044] Turning to the third embodiment illustrated in FIGS. 5 and 6, theblank is substantially similar to the embodiment illustrated in FIGS. 1and 2 comprises side panels, top and base panels and end flaps andtherefore only the differences are described in any detail. In thisembodiment an octagonal structure is formed. A first corner structurecomprises a pair of corner panels 210,202 hingeably connected torespective ones of top panel and base panel. Corner panel 202 ispositioned adjacent to its top panel but is separated by an ellipsoidalintermediate panel 204 hingeably connected to a top panel along foldline 206 and to corner panel along fold line 208. A glue flap 210 ishingeably connected to the adjacent side panel. Other corner structuresare identical to the corner structure described above and are thereforenot described in any greater detail.

[0045] The construction of the corner structure is carried out after thecarton is partly erected into a flat tubular structure as describedearlier. The corner structure is formed by folding corner panel 200 intoa substantially perpendicular relationship with base panel and byfolding corner panel 202 about fold line 208 and intermediate panelabout fold line 206 with top panel such that a substantiallyperpendicular relationship is formed between corner panel 202 and thetop panel. The corner panels 200 and 202 are placed into an overlappingrelationship and connected together by glue or other means known in theart. The corner structure is connected to the side panel by glue flap210. The other corner structures are constructed in the same way, asunderstood by those skilled in the art so that the carton is in itscompleted sealed form, as illustrated in FIG. 6.

[0046] Turning to the construction of the fourth embodiment illustratedin FIGS. 7 and 8 and the fifth embodiment illustrated in FIGS. 9 and 10,the blanks are substantially similar to the embodiments illustratedabove comprising side walls, top and base panels and end flaps andtherefore only the differences in each embodiment are described in anygreat detail.

[0047] In the fourth embodiment shown in FIG. 7, a corner panel 300 ishingeably connected to base panel along fold line 302. A pair of gussetpanels 304,306 is hingeably connected along a side edge of corner panel300 and to an end flap of the base panel. Likewise, a pair of gussetpanels 308 and 310 are hingeably connected to the opposing side edge ofcorner panel 300 and to a side edge of side panel interconnecting thetop panel and base panel.

[0048] In the fifth embodiment shown in FIG. 9, a corner panel 400 ishingeably connected to the top panel along fold line 402. A gusset panel404 is hingeably connected to an end flap being connected to the toppanel. Gusset panel 404 is substantially triangular in shape. A secondgusset panel 406 is hingeably connected to a side panel interconnectingthe top and base panels. The shape of the gusset panels can be alteredto provide overlapping arrangement depending upon manufacturingrequirements. The corner panel 406 is hingeably connected to gussetpanel 404 by connecting portion 408. Likewise, corner panel 400 ishingeably connected to gusset panel 406 by connected portion 410. Theother corner structures of each embodiment are formed in substantiallythe same way and are not therefore described in any greater detail.

[0049] The construction of the corner structure of the fourth and fifthembodiments is carried out after the carton is partly erected into aflat tubular structure as described earlier.

[0050] The corner structure in the fourth embodiment illustrated in FIG.7 and 8, is formed by folding the pair of gusset panels 304,306 into aface to face relationship with each other and the pair of gusset panels308 and 310 into face to face relationship such that the upper edge ofcorner panel 300 comes into contact with the free edge 312 of the toppanel and are connected together by means of a glue flap 314. It will beappreciated by those skilled in the art that the end flaps from the toppanel and base panel respectively are thus placed in an overlappingrelationship and can be connected together. Optionally, the gussetpanels can be secured to the side wall or end flap to provide a sealedcarrier, as illustrated in FIG. 8.

[0051] Turning to the construction of the corner structure of the fifthembodiment the connecting portion 408 is folded into an overlapping faceto face relationship with corner panel 400 and gusset panel 404.Likewise, connecting portion 410 is folded into an overlapping face toface relationship with corner panel 400 and gusset panel 406.Preferably, the corner panel 400 and gusset panels 404,406 are securedtogether by glue or other means known in the art. Gusset panel 404 isconnected to base panel by means of glue flap 412. The other cornerstructures are constructed in the same way and the end flaps securedtogether by glue or other means known in the art to provide a sealedcarrier as illustrated in FIG. 10.

[0052] Of course, the construction of the corner structures of any ofthe embodiments can be carried out at substantially the same time or, ifpreferred, one end can be constructed prior to inserting the pizza. Inaddition, the shape of the corner panels and gusset panels can beadapted according to the desired final shape of carton. Preferably thegusset panels are secured in a face-to-face relationship with top panel,base panel or, as the case may be, side panel to provide a fully sealedunit. The corner panels are intended to be load bearing so that cartonscan be stacked. By positioning the corner panels closer to the notionalcentre point C of the carton, shown in FIG. 2, a stronger carton,capable of supporting a greater load, can be provided.

[0053] The present invention and its preferred embodiments relate to aflat tubular structure which is shaped to provide a satisfactoryrigidity to hold items such as a pizza securely but with a degree offlexibility so that the load transferred from stacked cartons can bebetter absorbed by the carrier. The shape of the blank minimises theamount of paperboard required in each embodiment. The items can beapplied to the carrier by hand or by automatic machinery. It isanticipated that the invention can be applied to a variety of carriersand not limited to those of the flat tubular sort.

1. A carton for accommodating a pizza or the like, the carton comprisinga top panel, a base panel, a pair of oppositely disposed side panelsinterconnecting said top and said base panel to provide a flat tubularstructure, and closure arrangement including end flaps adjoining saidtop and said base panel and a corner closure structure at each corner ofthe carton including a plurality of overlapping gusset panels whereineach said gusset panel adjoins a respective said side panel, said endflap and one of said top panel or said base panel.
 2. A carton accordingto claim 1 , wherein said corner structure is adapted to provide asealed corner of said carton.
 3. A carton according to claim 1 , whereina connecting tab portion interconnects said gusset that adjoins saidbase panel or said top panel with at least one proximate said gussetthat adjoins said side panel and said end flap, respectively.
 4. Acarton according to claim 1 , wherein at least one of said gusset panelshas a substantially triangular configuration.
 5. A carton according toclaim 4 , wherein a connecting tab portion interconnects said gussetthat adjoins said base panel or said top panel with at least oneproximate said gusset that adjoins said side panel and said end flap,respectively.
 6. A carton according to claim 1 , wherein said cornerstructure is adapted to provide a sealed corner of said carton.
 7. Ablank for forming a flat tubular carton, the blank comprising a toppanel, a base panel, a pair of oppositely disposed side and end wallshingeably connected to one of said top panel and said base panel and acorner closure structure including a plurality of gusset panels eachadjoining a respective said side panel, said end flap and one of saidtop panel or said base panel for being disposed in overlapping conditionin the erected carton.
 8. The blank of claim 7 , wherein a connectingtab portion interconnects said gusset that adjoins said base panel orsaid top panel with at least one proximate said gusset that adjoins saidside panel and said end flap, respectively.
 9. The blank of claim 7 ,wherein at least one of said gusset panels has a substantiallytriangular configuration.
 10. The blank of claim 9 , wherein aconnecting tab portion interconnects said gusset that adjoins said basepanel or said top panel with at least one proximate said gusset thatadjoins said side panel and said end flap, respectively.